activity
20122026
most citedSpaces of Graphs, Boundary Groupoids and the Coarse Baum-Connes Conjecture

39 citations · 57 across the 8 of their papers we have counts for

collaborators

12 papers

math.GR2026

Lacunary hyperbolic groups with fast injectivity radius growth and enough loxodromic elements are selfless

Goulnara Arzhantseva, Martin Finn-Sell

We prove that a lacunary hyperbolic group with sufficient generics is selfless in the sense of Amrutam--Gao--Kunnawalkam Elayavalli--Patchell, provided the hyp…

math.OA2019

Representation theory of topological full groups of étale groupoids and paradoxicality

Vadim Alekseev, Martin Finn-Sell

We provide a unified treatment of several results concerning full groups of ample groupoids and paradoxical decompositions attached to them. This includes a criterion for the full…

math.GR2019

Controlled Analytic Properties and the Quantitative Baum-Connes Conjecture

Martin Finn-Sell

We show that the classical Baum-Connes assembly map is quantitatively an isomorphism for a class of lacunary hyperbolic groups, and we explain how to see that this class contains m…

math.GR2018

Unrestricted wreath products and sofic groups

Goulnara Arzhantseva, Federico Berlai, Martin Finn-Sell +1

We show that the unrestricted wreath product of a sofic group by an amenable group is sofic. We use this result to present an alternative proof of the known fact that any group ext…

math.GR2016★ 6 cited

Sofic boundaries of groups and coarse geometry of sofic approximations

Vadim Alekseev, Martin Finn-Sell

Sofic groups generalise both residually finite and amenable groups, and the concept is central to many important results and conjectures in measured group theory. We introduce a to…

math.OA2016★ 9 cited

Non-amenable principal groupoids with weak containment

Vadim Alekseev, Martin Finn-Sell

We construct examples of principal groupoids that have weak containment but are not amenable, thus answering questions by Claire Anantharaman-Delaroche and Rufus Willett.

math.MG2015★ 3 cited

The Asymptotic Dimension of Box Spaces for Elementary Amenable Groups

Martin Finn-Sell, Jianchao Wu

We show that the asymptotic dimension of box spaces behaves (sub)additively with respect to extensions of groups. As a result, we obtain that for an elementary amenable group, the…

math.GR2015

Almost quasi-isometries and more non-exact groups

Martin Finn-Sell

We study permanence results for almost quasi-isometries, the maps arising from the Gromov construction of finitely generated random groups that contain expanders (and hence that ar…

math.GR2014

Subsemigroup, ideal and congruence growth of free semigroups

Alex Bailey, Martin Finn-Sell, Robert Snocken

Using Rees index, the subsemigroup growth of free semigroups is investigated. Lower and upper bounds for the sequence are given and it is shown to have superexponential growth of s…

math.KT2014

On the Baum-Connes conjecture for Gromov monster groups

Martin Finn-Sell

We present a geometric approach to the Baum-Connes conjecture with coefficients for Gromov monster groups via a theorem of Khoskham and Skandalis. Secondly, we use recent results c…

math.KT2013

Fibred coarse embeddings, a-T-menability and the coarse analogue of the Novikov conjecture

Martin Finn-Sell

The connection between the coarse geometry of metric spaces and analytic properties of topological groupoids is well known. One of the main results of Skandalis, Tu and Yu is that…

math.KT2012★ 39 cited

Spaces of Graphs, Boundary Groupoids and the Coarse Baum-Connes Conjecture

Martin Finn-Sell, Nick Wright

We introduce a new variant of the coarse Baum-Connes conjecture designed to tackle coarsely disconnected metric spaces called the boundary coarse Baum-Connes conjecture. We prove t…